Handhelds Syncing w/ Web-Based Calendars?

hacker asks: "I have been asked many times over the past few years to support "web-based calendaring" with pilot-link, so people can syncronize their PalmOS handheld devices directly with 'online' calendaring software. The problem is...what calendaring software? I've looked at the various alternatives (PHP iCalendar, WebCal, and about two-dozen others) free and commercial, and none of them really offer a good, powerful, flexible way to integrate the same kind of data that resides on a Palm handheld device. I would write the conduit between Palm and calendaring software. Has anyone actually used a web-based calendaring product they like, and if so, which one, and why? Would the ability to syncronize your Palm handheld with your web-based calendaring software be useful?"